Effect of biomass particle size and air superficial velocity on the gasification process in a downdraft fixed bed gasifier. An experimental and modelling study

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.

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Development of a Chemical Equilibrium Model of the Downdraft Fixed Bed Gasification Process with known Product Temperature, Using air as an Oxidizing Agent

Ingenieria y Universidad ◽

10.11144/javeriana.iyu24.dcem ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

Daniel Andres Quintero-Coronel ◽

Edwin Edgardo Espinel-Blanco ◽

Eder Norberto Flórez-Solano

Keyword(s):

Chemical Equilibrium ◽

Equilibrium Model ◽

Fixed Bed ◽

Palm Kernel ◽

Outlet Temperature ◽

Reaction Products ◽

Gasification Process ◽

Downdraft Fixed Bed ◽

Gasification Reaction ◽

Chemical Equilibrium Model

A chemical equilibrium model for known outlet temperature of the products was carried out on a downdraft fixed bed gasifier. Biomass from oil palm kernel is used with proximate and ultimate analysis; the general gasification reaction takes into account the biomass moisture, the reaction products are formed by CH4, H2O, N2, CO, CO2 and H2. The model is described in detail and the equations are solved using the EES software. The model shows the results obtained for temperature ranges from 500 K to 1500 K and 1.0 atm. The model is validated by direct comparison of the gas composition with the results reported in the literature for similar conditions, obtaining favorable results.

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SIMULASI PENGARUH UKURAN PARTIKEL DAN EQUIVALENCE RATIO DALAM PROSES GASIFIKASI TANDAN KOSONG KELAPA SAWIT

Jurnal Kimia Terapan Indonesia ◽

10.14203/jkti.v17i2.26 ◽

2016 ◽

Vol 17 (2) ◽

pp. 101-109

Author(s):

Sabar Pangihutan Simanungkalit ◽

Dieni Mansur ◽

Nino Rinaldi

Keyword(s):

Particle Size ◽

Equivalence Ratio ◽

Fixed Bed ◽

Process Time ◽

Ansys Fluent ◽

Empty Fruit Bunches ◽

Carbon Efficiency ◽

Gasification Process ◽

Batch Simulation ◽

Gasification Efficiency

In this study, a simulation for gasification process of oil palm empty fruit bunches waste (OPEFB) using a fixed bed gasifier (throat downdraft) by varying the particle size of OPEFB and equivalence ratio (ER) was investigated. The rate of fuel consumption was 10 kg/h with air as the oxidizing medium and 1 hour process time for 1 batch. Simulation was performed with two-dimensional approach (2D) using Computational Fluid Dynamics (CFD) ANSYS FLUENT 14 software. Simulation results show that ideal amount of equivalence ratio (ER) for gasification process of OPEFB pellets with diameter (φ) of 6 mm and 8 mm is 0.1 ≤ ER ≤ 0.2. ER variation affects the higher heating value of syngas (HHV), the carbon efficiency (ηC), gasification efficiency and temperature distribution in the gasification reactor. Variations in particle size did not have a significant effect in the gasification process.Keywords: CFD, OPEFB gasification, particle size, equivalence ratio

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Effect of particle size and temperature on gasification performance of coconut and palm kernel shells in downdraft fixed-bed reactor

Energy ◽

10.1016/j.energy.2019.03.138 ◽

2019 ◽

Vol 175 ◽

pp. 931-940 ◽

Cited By ~ 11

Author(s):

Ahmad Zubair Yahaya ◽

Mahendra Rao Somalu ◽

Andanastuti Muchtar ◽

Shaharin Anwar Sulaiman ◽

Wan Ramli Wan Daud

Keyword(s):

Particle Size ◽

Fixed Bed ◽

Palm Kernel ◽

Fixed Bed Reactor ◽

Effect Of Particle Size ◽

Downdraft Fixed Bed ◽

Palm Kernel Shells

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Effect of Particle Size and Temperature on Pyrolysis of Palm Kernel Shell

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.35.22339 ◽

2018 ◽

Vol 7 (4.35) ◽

pp. 118

Author(s):

Khairunnisa Kamarul Zaman ◽

Vekes Balasundram ◽

Norazana Ibrahim ◽

Mohammad Dinie Muhaimin Samsudin ◽

Rafiziana Md. Kasmani ◽

...

Keyword(s):

Particle Size ◽

Thermal Behaviour ◽

Fixed Bed ◽

Palm Kernel ◽

Ash Content ◽

Maximum Temperature ◽

Pyrolysis Oil ◽

Biomass Ash ◽

Palm Kernel Shell ◽

Biomass Particle Size

Pyrolysis is a viable solution to curb the issue of growing lignocellulosic waste in the world through conversion to potential biofuel and bio-based chemicals. This study focused on the effect of biomass particle size on the feedstock characterisation, biomass ash content, thermal behaviour and pyrolysis products yield. The particle size ranges studied were <0.355, 0.355 to 0.710. 0.710 to 1.00 and 1.00 to 2.00 mm. Thermal behaviour was analysed using thermogravimetric analyser, and pyrolysis experiments were conducted in a fixed-bed pyrolyzer. TGA results show smaller particle size maximum temperature shifted to a lower temperature. From ashing, the results indicated that ash content is the highest at the smallest particle size, <0.355mm (2.8 wt.%). The gaseous yield was the highest in dpA (<0.355 mm) at a temperature of 600°C. The highest pyrolysis oil yield (50.1 wt.%) occurred at 400°C from dpA (<0.355mm). The highest char yield (33.70 wt.%) occurred at 400°C obtained from the largest particle size, dpD (1-2mm).

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Biomass gasification with CHP production: A review of state of the art technology and near future perspectives

Thermal Science ◽

10.2298/tsci120216066j ◽

2012 ◽

Vol 16 (suppl. 1) ◽

pp. 115-130 ◽

Cited By ~ 14

Author(s):

Goran Jankes ◽

Marta Trninic ◽

Mirjana Stamenic ◽

Tomislav Simonovic ◽

Nikola Tanasic ◽

...

Keyword(s):

State Of The Art ◽

Fixed Bed ◽

Biomass Gasification ◽

Economic Feasibility ◽

Biofuel Production ◽

Mature Stage ◽

Heating Value ◽

Gasification Process ◽

Downdraft Fixed Bed ◽

Near Future

This paper is a review of the state of the art of biomass gasification and the future of using biomass in Serbia and it presents researches within the project ?The Development of a CHP Plant with Biomass Gasification?. The concept of downdraft demonstration unit coupled with gas engine is adopted. Downdraft fixed-bed gasification is generally favored for CHP, owing to the simple and reliable gasifiers and low content of tar and dust in produced gas. The composition and quantity of gas and the amount of air are defined by modeling biomass residues gasification process. The gas (290-400m3/h for 0.5- 0.7MW biomass input) obtained by gasification at 800oC with air at atmospheric pressure contains 14% H2, 27% CO, 9% CO2, 2% CH4, and 48% N2, and its net heating value is 4.8-6 MJ/Nm3. The expected gasifier efficiency is up to 80%. The review of the work on biomass gasification has shown that the development of technology has reached the mature stage. There are CHP plants with biomass gasification operating as demonstration plants and several gasification demonstration units are successfully oriented to biofuel production. No attempt has been made here to address the economic feasibility of the system. Economics will be the part of a later work as firmer data are acquired.

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Gasification Process Using Downdraft Fixed-Bed Gasifier for Different Feedstock

10.5772/intechopen.96227 ◽

2021 ◽

Author(s):

Md. Emdadul Hoque ◽

Fazlur Rashid

Keyword(s):

Biomass Conversion ◽

Fixed Bed ◽

Gas Production ◽

Rice Husks ◽

Gasification Process ◽

Synthetic Gas ◽

Feasible Option ◽

Temperature Combustion ◽

Downdraft Fixed Bed ◽

Zone Temperature

The use of conventional fuels is decreasing globally due to its limited reserves and negative impact on the environment. The associated cost of conventional fuels is increasing owing to the higher demand for conventional fuels. Hence, utilization methods of biomass to generate energy are of growing interest. Among different biomass feedstocks, rice husks, waste plastics, and sawdust are significantly available in the global environment. The annual generation amount of rice husk is approximately 120 million tons worldwide, with an annual energy generation potential of 109 GJ with a heating value of 15 MJ/kg. The gasification process is assumed to be the most effective biomass conversion method that can generate synthetic gas to operate IC engines, fuel cells, and boilers. Synthetic gas production from biomass using a gasification process is a significant source of future energy. Downdraft fixed-bed gasifiers are considered as a feasible option of biomass conversion in the gasification process. By optimizing the operating conditions of downdraft fixed-bed gasifier, such as reaction zone temperature, combustion zone temperature, intake air temperature, airflow rate, the humidity of intake air, a significant amount of synthetic gas can be produced from rice husks, waste plastic material, and sawdust.

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